Rheostat.



UNITED STATES PATENT OFFICE.

WILLIAM G. YATES, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COM- PANY, A CORPORATION OF NEW YORK.

REEOSTAT.

Specification of Letters Patent.

Patented Jan. 19, 1909.

Application filed July 29, 1907. Serial N0. 386,150.

To all whom it may concern:

Be it known that 1, WILLIAM C. YATES, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Rheostats, of which the following is a specification. This invention relates to devices for controlling electric circuits and-has for'its object the provision of a device of this character in which the circuit of a dynamo electric machine, such as a motor or generator, may be controlled from a remote point by fine gradations in a reliable and efficient manner.

'One of the objects of my invention is to provide a regulator for electric circuits in which a large number ofsteps will be obtained without the necessity of constructing a s ecial rheostat of abnormal size.

carrying out my invention I connect two rheostats together in 'such a manner that they will be operated successively, the arrangement being such that when the limit of regulation on one is reached, the other rheostat is automatically brought into operation.

p In the accompanying drawings in which I have shown my invention embodied in a concrete form, Figure 1 is a plan view of my device, certain parts being removed in the in: terest of clearness, and Fig. 2 is a diagram of the circuit connections.

Referring to the drawings (Fig. 1) 1 is a supporting base or panel preferably of some insulating material, such as slate or soapstone. Upon this anel. I mount two rheo'- stats A and B, I rave found it convenient to mount these rheostats upon the same base although it should be understood that this arrangement is notessential to my invention. The two rheostats are identical in construction and operation so it will therefore be necessary to describe only one of them. The rheostat consists of the usual contact segments 2 forming terminals of the resistance 3 and arranged in the arc of a circle. In order to obtain a large number of steps on each rheostat, the segments are ex tended almost entirely around the circumference of the circle. A controlling arm 4 is pivoted at 5 so that its free end engages the contacts, and a conducting segment 6 arranged concentrically with the pivotal point of the" arm is engaged by a contact on said arm. A ring or disk 7 is pivoted at 5 and spring 13 draws the pawls to ether at their free ends, and a pin 14 fixedly mounted in the base projects upward between the pawls so as to engage one of them upon a slight movement of the arm 8 in either direction.

The arm 8 is vibrated back and forth by means of a pair of solenoids 15 and 16 o I rating upon a common core or plunger ro f1? The arm 8 is pivoted to this rod at 13 and is therefore vibrated in accordance with the movement of the rod, which in turn is con troll'ed by the solenoids. The circuits of these solenoids are controlled by spring-pressed flippers or switches 19 and 20, pivoted re spectively at the points 21 and 22. One and 0 each of these switches is provided with a projection 23 adapted to be engaged by a finger 24 on the arm 8 While the other end makes electrical contact with the osts 25 and 26. The circuits of the solenoi. s are also controlled by limit switches 27 and 28 mounted in a similar manner to the switches 1 9 and 20, and adapted to be engaged by the controllingarm 4 on the limit of its'travel in either direction so as to 0 enthe circuit a's'will be hereinafter describe A switch pivoted to the base at 29 has a contact arm 30 adapted to eng clip 31 and is provided .with a projection 32 extending into the path of the controlling arm 4. hen the controlling arm strikes the projection 32 going in a clockwise direction, the switch arm 30 moves into contact with clip 31. When the arm is returning in the opposite direction and engages the arm 33, t e arm 30 is returned to the supporting clip. The two rheostats A and B have this switch oppositely arranged for purposes hereinafter described.

The arrangement of circuits and the mode of o eration are as follows: When the switc arm 35 is closed on contact 36, the circuit of solenoid 15 is energized from the positive main and conductor 37 thence through switch 38 and switch 19 hack to the age a circuit being as follows:

negative main through conductor 38. This moves the arm 8 to the left, and the pawl 9 engaging the disk 7 moves the latter so as to carry the controlling arm 4 in a clockwise direction. As the arm 8 moves, the pin 14 remains stationary and the pawl 10 is therefore held stationary, a tension thus being placed upon the spring 13. l'l 'hen the arm has moved a distance to the left equal to the length of a step,t'he finger 24 engages the projection 23 on switch 19 a; 1 opens the circuit of solenoid '15 at conta ct stud 25. The arm then returns in response to the tension of the spring 13 to its central position. The circuit at stud is again closed and the operation is repeated. In this way the arm 8 vibrates back and forth advancing the disk? and moving the controlling arm in a clockwise direction step by step. This movement, of course, can be stopped at any time .by opening the switch 35, or immediatel reversed by closing the switch 35 on to the contact 39. in this way the resistance is thrown in series with the motoi field F, the from the field F through conductor it) to resistance 3 and arm 4 thence to the contact ring 6, conductor 41, arm 4, ring 6 and back to line through old 16 so that it will conductor 42. The switch 35 being kept closed on'contact 36, the arm 4 moves in a clockwise direction until all of the resistance 3 is cut in circuit, and the arm engages the projection 32 which moves the switch 30 into engagement with the clip 31, th reby energizing solenoid 15' as follows: from the positive main, conductor 37, clip 31, con doctor 43,solenoid 15,switch. 28,switcl1 19, conductor 44, conductor 38 and back to the negative main. Solenoid 15 is likewise energized at this time since it is necessary that the arm 4 shall move with suflicient power to operate the switch. hen this is done, however, the arm 4 engages the switch 28 and opens thecircuit of solenoid l5 and stops the movement of arm 4. The arm 4 now begins to advance in a clockwise direction step by etc in the same manner as that described witi reference to arm 4. As soon as the arm 4 leaves its initial position it engages switch 30 causing it to open or break contact with the clip 31. This 0 ens the circuit of solen e impossible to operate rheostatA in either direction after rheostat 13 leaves its initial position. The arm 4 corn tinu'es to-move to the right cutting resistance '3 in series with resistance 3, the circuit through the field now being as follows: con- 'ductor 40, res1stance3, arm 4 to ring 6, con-' ductor 41, resistance 3, arm l, ring 6 and conductor. 42 back to line. llhen the arm has traveled far enough to the right to cut all of the resistance in circuit, the circuit of solenoid 15 is opened at switch 28. g If the switch 35 is then moved on to contact 39,

be energized and the arm 4 driven backward in a counter-clockwise direction. As it comes back and closes switch 30, the circuit of solenoid 16 will again be completed and the arm 4 will travel in a countenclocirwise direction back to the starting position. In this way it will be seen that I have provided means whereby two rheostats are arranged so as to give all of the advantages of a regulator twice the size of one of them. The construction of large special regulators may thus be avoided and a number of standard regulators will be used connected in series.

it will be understood, of course, that various modifications of my invention will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which is set forth in the annexed claims.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. A controlling device for electric circuits comprising a plurality of automatically operated rheostats, and connections whereby one of said rheostats startsanother of said rheostats after a predetermined movement.

2. A controlling device for electric circuits comprising a plurality of automatically-operated rheostats, and connections whereby one of said rheostats is started by the movement of another of said rheostats to'a predetermined position.

3. A controlling device for electric circuits comprising a plurality oi rheostats, electric allycontrolled mechanisms for operatinv' each of said rheostats independently, an

connections whereby one of said mechanisms is energized to operate its rheostat after a predetermined movement of another of said rneostats.

i. A controllingdevice for electric circuits comprising a plurality of rheostats, electrically controlled mechanisms for operating each of said. rlieostats independently in two directions, and connections whereby one of said mechanisms is energized to operate its rheostat after a redetermined movement of another of said rlieostats.

5. A controlling device for electric circuits comprising a plurality of rheostats,,electrically controlled mechanisms for operating each of said rh'eostats independently, connections whereby one of said mechanisms is energized to operate its rheostat after a redetermined movement of another of sai rheo-.

operating ping said first mechanism after the second mechanism is started.

7. A controlling device for electric circuits comprising a plurality of rheostats, electrically controlled mechanisms for operating each of said rheostats independently step by step, connections whereby one of said mechanisms is energized to operate its rheostat after a predetermined movement of another of said rheostats, and means for stopping said first mechanism after the second mechanism is started.

8. A controlling device for electric circuits comprising a plurality of rheostats, electrically-controlled mechanisms for operating each ofsaid rheostats independently step by step in two directions, connections whereby one of said mechanisms is energized to operate its rheostat after a predetermined movement of another of said rheostats, and means for stopping said first mechanism after the second mechanism is started.

9. A controlling device for electric circuits comprising a plurality of rheostats, electrically controlled mechanisms for operating each of said rheostats independently step by ment of another of said rheostats, means for stopping said first mechanism after thesec- 0nd mechanism is started, and means for preventin the operation of said first rheostat when t e second rheostat is out of its initial position.

In Witness whereof, I have hereunto set my hand this 17th day of July, 1907.

WILLIAM C. YATES.

Witnesses:

BENJAMIN B. HULL, HELEN OnFoRn; 

